1
|
Al-Nashash H, Wong KL, ALL AH. Hypothermia effects on neuronal plasticity post spinal cord injury. PLoS One 2024; 19:e0301430. [PMID: 38578715 PMCID: PMC10997101 DOI: 10.1371/journal.pone.0301430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 03/15/2024] [Indexed: 04/07/2024] Open
Abstract
BACKGROUND SCI is a time-sensitive debilitating neurological condition without treatment options. Although the central nervous system is not programmed for effective endogenous repairs or regeneration, neuroplasticity partially compensates for the dysfunction consequences of SCI. OBJECTIVE AND HYPOTHESIS The purpose of our study is to investigate whether early induction of hypothermia impacts neuronal tissue compensatory mechanisms. Our hypothesis is that although neuroplasticity happens within the neuropathways, both above (forelimbs) and below (hindlimbs) the site of spinal cord injury (SCI), hypothermia further influences the upper limbs' SSEP signals, even when the SCI is mid-thoracic. STUDY DESIGN A total of 30 male and female adult rats are randomly assigned to four groups (n = 7): sham group, control group undergoing only laminectomy, injury group with normothermia (37°C), and injury group with hypothermia (32°C +/-0.5°C). METHODS The NYU-Impactor is used to induce mid-thoracic (T8) moderate (12.5 mm) midline contusive injury in rats. Somatosensory evoked potential (SSEP) is an objective and non-invasive procedure to assess the functionality of selective neuropathways. SSEP monitoring of baseline, and on days 4 and 7 post-SCI are performed. RESULTS Statistical analysis shows that there are significant differences between the SSEP signal amplitudes recorded when stimulating either forelimb in the group of rats with normothermia compared to the rats treated with 2h of hypothermia on day 4 (left forelimb, p = 0.0417 and right forelimb, p = 0.0012) and on day 7 (left forelimb, p = 0.0332 and right forelimb, p = 0.0133) post-SCI. CONCLUSION Our results show that the forelimbs SSEP signals from the two groups of injuries with and without hypothermia have statistically significant differences on days 4 and 7. This indicates the neuroprotective effect of early hypothermia and its influences on stimulating further the neuroplasticity within the upper limbs neural network post-SCI. Timely detection of neuroplasticity and identifying the endogenous and exogenous factors have clinical applications in planning a more effective rehabilitation and functional electrical stimulation (FES) interventions in SCI patients.
Collapse
Affiliation(s)
- Hasan Al-Nashash
- Department of Electrical Engineering, College of Engineering, American University of Sharjah, Sharjah, United Arab Emirates
| | - Ka-Leung Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, China
| | - Angelo H. ALL
- Department of Chemistry, Faculty of Science, Hong Kong Baptist University, Hong Kong, China
| |
Collapse
|
2
|
Chen Z, Yang Y, Han Y, Wang X. Neuroprotective Effects and Mechanisms of Senegenin, an Effective Compound Originated From the Roots of Polygala Tenuifolia. Front Pharmacol 2022; 13:937333. [PMID: 35924058 PMCID: PMC9341472 DOI: 10.3389/fphar.2022.937333] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/24/2022] [Indexed: 11/13/2022] Open
Abstract
Senegenin is the main bioactive ingredient isolated from the dried roots of Polygala tenuifolia Willd. In recent years, senegenin has been proved to possess a variety of pharmacological activities, such as anti-oxidation, anti-inflammation, anti-apoptosis, enhancement of cognitive function. Besides, it has a good development prospect for the treatment of neurodegenerative diseases, depression, osteoporosis, cognitive dysfunction, ischemia-reperfusion injury and other diseases. However, there is no systematic literature that fully demonstrates the pharmacological effects of senegenin. In order to meet the needs of new drug research and precise medication, this review summarized the neuroprotective effects, mechanisms and gastrointestinal toxicity of senegenin based on the literatures published from the past 2 decades. In addition, an in-depth analysis of the existing problems in the current research as well as the future research directions have been conducted in order to provide a basis for the clinical application of this important plant extract.
Collapse
|
3
|
Neuroprotective Role of Hypothermia in Acute Spinal Cord Injury. Biomedicines 2022; 10:biomedicines10010104. [PMID: 35052784 PMCID: PMC8773047 DOI: 10.3390/biomedicines10010104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/30/2021] [Accepted: 12/30/2021] [Indexed: 11/16/2022] Open
Abstract
Even nowadays, the question of whether hypothermia can genuinely be considered therapeutic care for patients with traumatic spinal cord injury (SCI) remains unanswered. Although the mechanisms of hypothermia action are yet to be fully explored, early hypothermia for patients suffering from acute SCI has already been implemented in clinical settings. This article discusses measures for inducing various forms of hypothermia and summarizes several hypotheses describing the likelihood of hypothermia mechanisms of action. We present our objective neuro-electrophysiological results and demonstrate that early hypothermia manifests neuroprotective effects mainly during the first- and second-month post-SCI, depending on the severity of the injury, time of intervening, duration, degree, and modality of inducing hypothermia. Nevertheless, eventually, its beneficial effects gradually but consistently diminish. In addition, we report potential complications and side effects for the administration of general hypothermia with a unique referment to the local hypothermia. We also provide evidence that instead of considering early hypothermia post-SCI a therapeutic approach, it is more a neuroprotective strategy in acute and sub-acute phases of SCI that mostly delay, but not entirely avoid, the natural history of the pathophysiological events. Indeed, the most crucial rationale for inducing early hypothermia is to halt these devastating inflammatory and apoptotic events as early and as much as possible. This, in turn, creates a larger time-window of opportunity for physicians to formulate and administer a well-designed personalized treatment for patients suffering from acute traumatic SCI.
Collapse
|
4
|
All AH, Al-Nashash H. Comparative analysis of functional assessment for contusion and transection models of spinal cord injury. Spinal Cord 2021; 59:1206-1209. [PMID: 34493803 DOI: 10.1038/s41393-021-00698-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN Descriptive secondary analysis of two spinal cord injury (SCI) animal models. OBJECTIVES To compare the somatosensory evoked potential (SSEP) and motor behavioral (BBB) assessments of the two most used rodent SCI models (contusion and transection), to elucidate their functional similarity and differences over the acute phase of 3 weeks. SETTING Neuro-electrophysiology SSEP and motor behavioral BBB assessments are used to provide a comparative analysis of the functional changes among various severities of contusion and transection SCI. METHODS Adult male and female rats randomly grouped (n = 5) as following: mild (6.25 mm), moderate (12.5 mm), severe (25 mm), and very severe (50 mm) contusion as well as right T10 hemi-transection (RxI), left T8 and right T10 double hemi-transection (DxI), and T8 complete transection (CxI) injuries, plus the control group (laminectomy with no injury). Animal weight, body temperature, anesthesia, surgical procedures, electrophysiological SSEP monitoring, locomotion BBB scoring, and statistical analysis were identical among all animal groups. RESULTS Statistical analysis of the SSEP and BBB data from both contusion and transection injury models indicate significant differences (P < 0.05). The results also show remarkable similarity for the severe and very severe contusion injuries to the complete transection, the moderate contusion injury to the double hemi-transection, and the mild contusion injury to the T10 hemi-transection injury. CONCLUSION Although contusion and transection spinal cord injuries have two completely different pathophysiologies, their injury progress during acute phase follow a similar trend.
Collapse
Affiliation(s)
- Angelo H All
- Department of Chemistry, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
| | - Hasan Al-Nashash
- Department of Electrical Engineering, College of Engineering, American University of Sharjah, University City, Sharjah, UAE.
| |
Collapse
|
5
|
All AH, Luo S, Liu X, Al-Nashash H. Effect of thoracic spinal cord injury on forelimb somatosensory evoked potential. Brain Res Bull 2021; 173:22-27. [PMID: 33991605 DOI: 10.1016/j.brainresbull.2021.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 05/06/2021] [Accepted: 05/08/2021] [Indexed: 10/21/2022]
Abstract
In this paper, we investigate the forelimbs somatosensory evoked potential (SSEP) signals, which are representative of the integrity of ascending sensory pathways and their stability as well as function, recorded from corresponding cortices, post thoracic spinal cord injury (SCI). We designed a series of distinctive transection SCI to investigate whether forelimbs SSEPs change after right T10 hemi-transection, T8 and T10 double hemi-transection and T8 complete transection in rat model of SCI. We used electrical stimuli to stimulate median nerves and recorded SSEPs from left and right somatosensory areas of both cortices. We monitored pre-injury baseline and verified changes in forelimbs SSEP signals on Days 4, 7, 14, and 21 post-injury. We previously characterized hindlimb SSEP changes for the abovementioned transection injuries. The focus of this article is to investigate the quality and quantity of changes that may occur in the forelimb somatosensory pathways post-thoracic transection SCI. It is important to test the stability of forelimb SSEPs following thoracic SCI because of their potential utility as a proxy baseline for the traumatic SCIs in clinical cases wherein there is no opportunity to gather baseline of the lower extremities. We observed that the forelimb SSEP amplitudes increased following thoracic SCI but gradually returned to the baseline. Despite changes found in the raw signals, statistical analysis found forelimb SSEP signals become stable relatively soon. In summary, though there are changes in value (with p > 0.05), they are not statistically significant. Therefore, the null hypothesis that the mean of the forelimb SSEP signals are the same across multiple days after injury onset cannot be rejected during the acute phase.
Collapse
Affiliation(s)
- Angelo H All
- Department of Chemistry, Faculty of Science, Hong Kong Baptist University, Room RRS844, Sir Run Run Shaw Building, Ho Sin Hang Campus, Hong Kong.
| | - Shiyu Luo
- Department of Biomedical Engineering, Johns Hopkins University, Traylor Building, 720 Rutland Ave., Baltimore, MD, 21205, USA.
| | - Xiaogang Liu
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore; The N.1 Institute for Health, National University of Singapore, Singapore.
| | - Hasan Al-Nashash
- Department of Electrical Engineering, College of Engineering, American University of Sharjah, ESB-2018, Engineering Science Building, American University of Sharjah, University City, Sharjah, 26666, United Arab Emirates.
| |
Collapse
|
6
|
Su S, Chai G, Shu X, Sheng X, Zhu X. Electrical stimulation-induced SSSEP as an objective index to evaluate the difference of tactile acuity between the left and right hand. J Neural Eng 2020; 17:016053. [PMID: 31801122 DOI: 10.1088/1741-2552/ab5ee9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The objective of this study is to propose an objective index to evaluate the difference of tactile acuity between the left and right hand based on steady-state somatosensory evoked potential (SSSEP). APPROACH Two kinds of tactile sensations (vibration and pressure) with three levels of intensities (low/medium/high) were evoked on two finger areas of the left or right hand (thumb and index for healthy hands, thumb and index-projected areas for disabled hands) via transcutaneous electrical nerve stimulation (TENS). Three forearm amputees and 13 able-bodied subjects were recruited to discriminate the specific level and area of the applied stimulation. Electroencephalography was adopted to simultaneously record the somatosensory cortex response to TENS. We assessed the discrimination performance (discrimination accuracy rate (AR) and response time (RT)) to quantify the tactile acuity, while the evoked SSSEP was synchronously analyzed. Linear regression analyses were performed between the difference of SSSEP amplitudes and the difference of discrimination performance for the left and right hand stimulation. MAIN RESULTS Frequency domain analysis revealed that SSSEP amplitude increased with the increase of the stimulation intensity. There were positive correlations between the difference of SSSEP amplitudes and the difference of ARs for the left and right hand stimulation in the sensations of vibration (R 2 = 0.6389 for able-bodied subjects, R 2 = 0.5328 for amputees) and pressure (R 2 = 0.6102 for able-bodied subjects, R 2 = 0.5452 for amputees), respectively. Significance The SSSEP amplitude could be used as an objective index to evaluate the difference of the tactile acuity between the left and right hand and has the potential to be applied in sensory rehabilitation for amputees or stroke patients.
Collapse
Affiliation(s)
- Shiyong Su
- State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | | | | | | | | |
Collapse
|
7
|
A Review of Functional Electrical Stimulation Treatment in Spinal Cord Injury. Neuromolecular Med 2020; 22:447-463. [DOI: 10.1007/s12017-019-08589-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 12/28/2019] [Indexed: 12/11/2022]
|
8
|
All AH, Al Nashash H, Mir H, Luo S, Liu X. Characterization of transection spinal cord injuries by monitoring somatosensory evoked potentials and motor behavior. Brain Res Bull 2019; 156:150-163. [PMID: 31866455 DOI: 10.1016/j.brainresbull.2019.12.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 01/20/2023]
Abstract
Standardization of spinal cord injury (SCI) models is crucial for reproducible injury in research settings and their objective assessments. Basso, Beattie and Bresnahan (BBB) scoring, the traditional behavioral evaluation method, is subjective and susceptible to human error. On the other hand, neuro-electrophysiological monitoring, such as somatosensory evoked potential (SSEP), is an objective assessment method that can be performed continuously for longitudinal studies. We implemented both SSEP and BBB assessments on transection SCI model. Five experimental groups are designed as follows: left hemi-transection at T8, right hemi-transection at T10, double hemi-transection at left T8 and right T10, complete transection at T8 and control group which receives only laminectomy with intact dura and no injury on spinal cord parenchyma. On days 4, 7, 14 and 21 post-injury, first BBB scores in awake and then SSEP signals in anesthetized rats were obtained. Our results show SSEP signals and BBB scores are both closely associated with transection model and injury progression. However, the two assessment modalities demonstrate different sensitivity in measuring injury progression when it comes to late-stage double hemi-transection, complete transection and hemi-transection injury. Furthermore, SSEP amplitudes are found to be distinct in different injury groups and the progress of their attenuation is increasingly rapid with more severe transection injuries. It is evident from our findings that SSEP and BBB methods provide distinctive and valuable information and could be complementary of each other. We propose incorporating both SSEP monitoring and conventional BBB scoring in SCI research to more effectively standardize injury progression.
Collapse
Affiliation(s)
- Angelo H All
- Department of Biomedical Engineering, Johns Hopkins University, Traylor Building, 720 Rutland Ave., Baltimore, Maryland, 21205, USA; SINAPSE Institute, National University of Singapore, Singapore.
| | - Hasan Al Nashash
- Department of Electrical Engineering, College of Engineering, American University of Sharjah, Engineering Building Left, Sharjah, 26666, United Arab Emirates.
| | - Hasan Mir
- Department of Electrical Engineering, College of Engineering, American University of Sharjah, Engineering Building Left, Sharjah, 26666, United Arab Emirates
| | - Shiyu Luo
- Department of Biomedical Engineering, Johns Hopkins University, Traylor Building, 720 Rutland Ave., Baltimore, Maryland, 21205, USA
| | - Xiaogang Liu
- Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| |
Collapse
|
9
|
Cui H, Li H, Li G, Kang C, Yao X, Feng S, Hu Y. Utility of Trial-to-Trial Latency Variability of Somatosensory Evoked Potentials for Diagnosis of Spinal Cord Demyelination. J Neurotrauma 2019; 36:3356-3362. [PMID: 31030618 DOI: 10.1089/neu.2018.6293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Hongyan Cui
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Hanlei Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Guangsheng Li
- Spinal division, Department of Orthopaedics, Affiliated Hospital of Guangdong Medical University, Guangdong, China
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong, China
| | - Cheng Kang
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong, China
| | - Xue Yao
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Shiqing Feng
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Yong Hu
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
- Spinal division, Department of Orthopaedics, Affiliated Hospital of Guangdong Medical University, Guangdong, China
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong, China
| |
Collapse
|
10
|
Cheung PWH, Hu Y, Cheung JPY. Novel compression rat model for developmental spinal stenosis. J Orthop Res 2019; 37:1090-1100. [PMID: 30644588 DOI: 10.1002/jor.24221] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 01/02/2019] [Indexed: 02/04/2023]
Abstract
Developmental spinal stenosis (DSS) is characterized by pre-existing circumferential narrowing of the bony spinal canal which predisposes neural tissue to compression. This study aims to create a reproducible animal model mimicking DSS for investigation of its pathoanatomy. Developmental spinal canal constriction was simulated using circumferential compression. Eighteen female Sprague-Dawley rats (13.0-14.5 weeks-old) underwent circumferential compression at L4-L5 using silicone sheets; or dorsal compression using overlapping silicone sheets; or as controls. A series of outcome scores were used for locomotor function assessment, together with electrophysiological and histological assessment. Assessment time-points were at preoperative, postoperative 1-week, 2-weeks, 3-weeks, 1-month, and pre-sacrifice. Statistical analyses were performed. At all postoperative time-points, circumferential group had the worst mean Basso, Beattie and Bresnahan locomotor scores with significant difference from the control group (p < 0.05), as well as the lowest mean Louisville Swim Scale scores, as compared to the dorsal (p < 0.05) and to the control (p < 0.01) groups. Circumferential group had worse mean foot fault score for both hindlimbs (p < 0.01 to p < 0.05) and highest error rate in foot placement accuracy, especially higher than dorsal (p < 0.05) and control (p < 0.05) groups at pre-sacrifice. Electrophysiological assessment revealed postoperative increase in P1 latency was higher in circumferential than dorsal compression. Highest postoperative mean P1 latency was observed for both paws at all postoperative time-points for circumferential group (except at postoperative 1-week). Circumferential group had lower myelin-to-axonal area ratio and higher g-ratio than both the dorsal and control groups (p < 0.001). For each study group, hindlimb P1 latency and P1-N1 amplitude were each correlated with g-ratio (p < 0.05); and mean myelin-to-axonal area ratio correlated with P1 latency of both hindlimbs (p < 0.05). Based on these more severe axonal demyelination and neurological deficits, a valid DSS rat model is created with somatosensory evoked potential neuro-monitoring technique. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
Collapse
Affiliation(s)
- Prudence W H Cheung
- Department of Orthopaedics and Traumatology, The University of Hong Kong, 5/F, Professorial Block, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong SAR, China
| | - Yong Hu
- Department of Orthopaedics and Traumatology, The University of Hong Kong, 5/F, Professorial Block, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong SAR, China
| | - Jason P Y Cheung
- Department of Orthopaedics and Traumatology, The University of Hong Kong, 5/F, Professorial Block, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong SAR, China
| |
Collapse
|
11
|
Yu YG, Yang J, Cheng XH, Shang W, Zhao BH, Zhao F, Chen ZG, Huang ZH. The protection of acute spinal cord injury by subarachnoid space injection of Danshen in animal models. J Spinal Cord Med 2019; 42:355-359. [PMID: 29920172 PMCID: PMC6522962 DOI: 10.1080/10790268.2018.1468583] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
CONTEXT/OBJECTIVE Following acute spinal cord injury (ASCI) in rabbits, subarachnoid space injection of Danshen was performed to protect the neurological damage. In this study, we established rabbit models of spinal cord injury using a modified Allen's method. DESIGN After the operation introducing the injuries, the rabbits were randomized into two different groups, control group (normal saline, NS) and Danshen, a component extracted from Chinese herb, treatment group. Each rabbit was supplied with either the drug or placebo at 0.3 ml/kg each day through subarachnoid cavity. SETTING Rabbit model of acute spinal cord injury were used for the response to Danshen treatment. PARTICIPANTS Total 48 Chinese rabbits aged four∼ five months old provided by Experimental Animal Center of Hubei Province were used for this study. INTERVENTIONS Danshen drug or placebo was administered via a silicon tube embedded under the spinal dura mater to administer the drugs into subarachnoid cavity. OUTCOME MEASURES After the treatment, damage indicators including cell apoptosis, morphological changes and oxidative damages were assessed. RESULTS We found out that cell apoptosis was decreased after Danshen injection as determined by downregulation of apoptosis index (AI) by TUNEL analysis as well as propidium iodide (PI) percentage by FACS analysis. In the meanwhile, we observed cells after the treatment have increased numbers of BCL-2 positive cells, this indicated the antiapoptotic gene expression is increased after Danshen treatment. When we check the oxidative damage indicators, we found superoxide dismutase (SOD) was increased and malondiadehyde (MDA) levels were decreased after the treatment. CONCLUSION Danshen can protect ASCI through inhibition of oxidative damage in the injured cells and thus reduce the subsequent cell apoptosis in the spinal.
Collapse
Affiliation(s)
- Yong-Gui Yu
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Jian Yang
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Xin-Hua Cheng
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China,Correspondence to: Xin-Hua Cheng, Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, No. 39 Middle Chaoyang Road, Shiyan, Hubei, 442000, China; Ph: +86-719-8637636.
| | - Wei Shang
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Bing-Hao Zhao
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Fei Zhao
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Zhi-Guo Chen
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Zhen-Hua Huang
- Department of Microscopic Orthopaedic, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| |
Collapse
|
12
|
Mattucci S, Speidel J, Liu J, Ramer MS, Kwon BK, Tetzlaff W, Oxland TR. Development of a traumatic cervical dislocation spinal cord injury model with residual compression in the rat. J Neurosci Methods 2019; 322:58-70. [PMID: 30951755 DOI: 10.1016/j.jneumeth.2019.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Preclinical spinal cord injury models do not represent the wide range of biomechanical factors seen in human injuries, such as spinal level, injury mechanism, velocity of spinal cord impact, and residual compression. These factors may be responsible for differences observed between experimental and clinical study results, especially related to the controversial issue of timing of surgical decompression. NEW METHOD Somatosensory Evoked Potentials were used to: a) characterize residual compression depths in a dislocation model, and b) evaluate the physiological effect of whether or not the spinal cord was decompressed following the initial injury, prior to the application of residual compression. Modifications to vertebral clamps and the development of a novel surgical frame allowed us to conduct surgical and injury procedures in a controlled manner without the risk of additional damage to the spinal cord. Behavioural outcomes were evaluated following varying dislocation displacements, in addition to the survivability of 4 h of residual compression following a traumatic injury. RESULTS Residual compression immediately following the initial dislocation demonstrated significantly different electrophysiological response compared to when the residual compression was delayed. COMPARISON WITH EXISTING METHOD There are currently no other residual compression models that utilize a dislocation injury mechanism. Many residual compression studies have demonstrated the effectiveness of early decompression, however the compression of the spinal cord is often not representative of clinical traumatic injuries. Preclinical studies typically model residual compression using a sustained force through quasi-static application, when human injuries often occur at high velocities, followed by a sustained displacement occlusion of the spinal canal. CONCLUSIONS This study has validated several novel procedural approaches and injury parameters, and provided critical details to implement in the development of a traumatic cervical dislocation SCI model with residual compression.
Collapse
Affiliation(s)
- Stephen Mattucci
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Jason Speidel
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Matt S Ramer
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Brian K Kwon
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Thomas R Oxland
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| |
Collapse
|
13
|
Teh DBL, Chua SM, Prasad A, Kakkos I, Jiang W, Yue M, Liu X, All AH. Neuroprotective assessment of prolonged local hypothermia post contusive spinal cord injury in rodent model. Spine J 2018; 18:507-514. [PMID: 29074466 DOI: 10.1016/j.spinee.2017.10.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/26/2017] [Accepted: 10/16/2017] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Although general hypothermia is recognized as a clinically applicable neuroprotective intervention, acute moderate local hypothermia post contusive spinal cord injury (SCI) is being considered a more effective approach. Previously, we have investigated the feasibility and safety of inducing prolonged local hypothermia in the central nervous system of a rodent model. PURPOSE Here, we aimed to verify the efficacy and neuroprotective effects of 5 and 8 hours of local moderate hypothermia (30±0.5°C) induced 2 hours after moderate thoracic contusive SCI in rats. STUDY DESIGN Rats were induced with moderate SCI (12.5 mm) at its T8 section. Local hypothermia (30±0.5°C) was induced 2 hours after injury induction with an M-shaped copper tube with flow of cold water (12°C), from the T6 to the T10 region. Experiment groups were divided into 5-hour and 8-hour hypothermia treatment groups, respectively, whereas the normothermia control group underwent no hypothermia treatment. METHODS The neuroprotective effects were assessed through objective weekly somatosensory evoked potential (SSEP) and motor behavior (basso, beattie and bresnahan Basso, Beattie and Bresnahan (BBB) scoring) monitoring. Histology on spinal cord was performed until at the end of day 56. All authors declared no conflict of interest. This work was supported by the Singapore Institute for Neurotechnology Seed Fund (R-175-000-121-733), National University of Singapore, Ministry of Education, Tier 1 (R-172-000-414-112.). RESULTS Our results show significant SSEP amplitudes recovery in local hypothermia groups starting from day 14 post-injury onward for the 8-hour treatment group, which persisted up to days 28 and 42, whereas the 5-hour group showed significant improvement only at day 42. The functional improvement plateaued after day 42 as compared with control group of SCI with normothermia. This was supported by both 5-hour and 8-hour improvement in locomotion as measured by BBB scores. Local hypothermia also observed insignificant changes in its SSEP latency, as compared with the control. In addition, 5- and 8-hour hypothermia rats' spinal cord showed higher percentage of parenchyma preservation. CONCLUSIONS Early local moderate hypothermia can be induced for extended periods of time post SCI in the rodent model. Such intervention improves functional electrophysiological outcome and motor behavior recovery for a long time, lasting until 8 weeks.
Collapse
Affiliation(s)
- Daniel Boon Loong Teh
- Department of Medicine & Singapore Institute of Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Dr, 5-COR, Singapore 117456, Singapore
| | - Soo Min Chua
- Department of Medicine & Singapore Institute of Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Dr, 5-COR, Singapore 117456, Singapore
| | - Ankshita Prasad
- Department of Medicine & Singapore Institute of Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Dr, 5-COR, Singapore 117456, Singapore; Department of Biomedical Engineering, National University of Singapore, E4, 4 Engineering Dr 3, Singapore 117583, Singapore
| | - Ioannis Kakkos
- Department of Electrical and Computing Engineering, National Technical University of Athens, Zografos, 15773, Athens, Greece
| | - Wenxuan Jiang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Mu Yue
- Department of Statistics and Applied Probability, National University of Singapore, Level 7, Block S16,6 Science Dr 2, Singapore 117546, Singapore
| | - Xiaogang Liu
- Department of Chemistry, National University of Singapore, 3 Science Dr 3, Singapore 117543, Singapore
| | - Angelo Homayoun All
- Department of Medicine & Singapore Institute of Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Dr, 5-COR, Singapore 117456, Singapore; Department of Biomedical Engineering and Department of Neurology, John Hopkins School of Medicine, 701C Rutland Ave 720, Baltimore, MD 21205, USA.
| |
Collapse
|
14
|
Vayrynen E, Noponen K, Vipin A, Thow XY, Al-Nashash H, Kortelainen J, All A. Automatic Parametrization of Somatosensory Evoked Potentials With Chirp Modeling. IEEE Trans Neural Syst Rehabil Eng 2016; 24:981-992. [DOI: 10.1109/tnsre.2016.2525829] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
15
|
Vipin A, Thow XY, Mir H, Kortelainen J, Manivannan J, Al-Nashash H, All AH. Natural Progression of Spinal Cord Transection Injury and Reorganization of Neural Pathways. J Neurotrauma 2016; 33:2191-2201. [PMID: 27159651 DOI: 10.1089/neu.2015.4383] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The spinal cord injury (SCI) transection model accurately represents traumatic laceration and has been widely used to study the natural history and reorganization of neuropathways and plasticity in the central nervous system (CNS). This model is highly reproducible, which makes it ideal for studying the progression of injury as well as endogenous recovery and plasticity in the CNS. Five experimental groups of transection injury were designed: left hemitransection; right hemitransection; double hemitransection; complete transection injuries; and laminectomy-only control. We used somatosensory evoked potentials (SSEPs) as an objective electrophysiological assessment tool and motor behavior testing (Basso, Beattie, and Bresnahan [BBB] scoring) to functionally assess the neural pathways post-injury. Histological examinations were carried out to investigate the extent of injury and spinal cord morphological changes. Significant (p < 0.05) electrophysiological changes were observed and were verified by an increase in SSEP amplitude in somatosensory cortices for all four injury groups during days 4 and 7 post-injury. Degree of plasticity among the groups was distinguished by changes in SSEP amplitude and BBB scores. Our results support our previous published findings (using a contusive model of SCI), which shows that the reorganization of neuropathways and plasticity persist in time and are not transient phenomena. SSEPs are a reliable tool to assess the functionality of neural pathways and their projections to higher CNS structures such as the cortices. They enable us to determine residual function and the changes within the CNS post-injury and consistently track these events over time. The results from our study provide supporting evidence for the presence of neuronal network reorganization and plasticity in the CNS after transection SCI.
Collapse
Affiliation(s)
- Ashwati Vipin
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore
| | - Xin Yuan Thow
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore
| | - Hasan Mir
- 2 Department of Electrical Engineering, American University of Sharjah , Sharjah, United Arab Emirates
| | - Jukka Kortelainen
- 3 Department of Computer Science and Engineering University of Oulu , Oulu, Finland
| | - Janani Manivannan
- 4 Department of Orthopedic Surgery, National University of Singapore , Singapore
| | - Hasan Al-Nashash
- 2 Department of Electrical Engineering, American University of Sharjah , Sharjah, United Arab Emirates
| | - Angelo H All
- 4 Department of Orthopedic Surgery, National University of Singapore , Singapore .,5 Department of Biomedical Engineering, National University of Singapore , Singapore .,6 Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland.,7 Department of Neurology, Johns Hopkins University, Baltimore, Maryland
| |
Collapse
|
16
|
Zhang SQ, Wu MF, Gu R, Liu JB, Li Y, Zhu QS, Jiang JL. Senegenin inhibits neuronal apoptosis after spinal cord contusion injury. Neural Regen Res 2016; 11:657-63. [PMID: 27212931 PMCID: PMC4870927 DOI: 10.4103/1673-5374.180754] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Senegenin has been shown to inhibit neuronal apoptosis, thereby exerting a neuroprotective effect. In the present study, we established a rat model of spinal cord contusion injury using the modified Allen's method. Three hours after injury, senegenin (30 mg/g) was injected into the tail vein for 3 consecutive days. Senegenin reduced the size of syringomyelic cavities, and it substantially reduced the number of apoptotic cells in the spinal cord. At the site of injury, Bax and Caspase-3 mRNA and protein levels were decreased by senegenin, while Bcl-2 mRNA and protein levels were increased. Nerve fiber density was increased in the spinal cord proximal to the brain, and hindlimb motor function and electrophysiological properties of rat hindlimb were improved. Taken together, our results suggest that senegenin exerts a neuroprotective effect by suppressing neuronal apoptosis at the site of spinal cord injury.
Collapse
Affiliation(s)
- Shu-Quan Zhang
- Department of Orthopedics, Nankai Hospital, Tianjin, China
| | - Min-Fei Wu
- Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Rui Gu
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China
| | - Jia-Bei Liu
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China
| | - Ye Li
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China
| | - Qing-San Zhu
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China
| | - Jin-Lan Jiang
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China; Scientific Research Center, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China
| |
Collapse
|
17
|
Qu X, Yan J, Li X, Zhang P, Liu X. Topography of Synchronization of Somatosensory Evoked Potentials Elicited by Stimulation of the Sciatic Nerve in Rat. Front Comput Neurosci 2016; 10:43. [PMID: 27199728 PMCID: PMC4854893 DOI: 10.3389/fncom.2016.00043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 04/18/2016] [Indexed: 01/14/2023] Open
Abstract
Purpose: Traditionally, the topography of somatosensory evoked potentials (SEPs) is generated based on amplitude and latency. However, this operation focuses on the physical morphology and field potential-power, so it suffers from difficulties in performing identification in an objective manner. In this study, measurement of the synchronization of SEPs is proposed as a method to explore brain functional networks as well as the plasticity after peripheral nerve injury. Method: SEPs elicited by unilateral sciatic nerve stimulation in twelve adult male Sprague-Dawley (SD) rats in the normal group were compared with SEPs evoked after unilateral sciatic nerve hemisection in four peripheral nerve injured SD rats. The characterization of synchronized networks from SEPs was conducted using equal-time correlation, correlation matrix analysis, and comparison to randomized surrogate data. Eigenvalues of the correlation matrix were used to identify the clusters of functionally synchronized neuronal activity, and the participation index (PI) was calculated to indicate the involvement of each channel in the cluster. The PI value at the knee point of the PI histogram was used as a threshold to demarcate the cortical boundary. Results: Ten out of the twelve normal rats showed only one synchronized brain network. The remaining two normal rats showed one strong and one weak network. In the peripheral nerve injured group, only one synchronized brain network was found in each rat. In the normal group, all network shapes appear regular and the network is largely contained in the posterior cortex. In the injured group, the network shapes appear irregular, the network extends anteriorly and posteriorly, and the network area is significantly larger. There are considerable individual variations in the shape and location of the network after peripheral nerve injury. Conclusion: The proposed method can detect functional brain networks. Compared to the results of the traditional SEP-morphology-based analysis method, the synchronized functional network area is much larger. Furthermore, the proposed method can also characterize the rapid cortical plasticity after a peripheral nerve is acutely injured.
Collapse
Affiliation(s)
- Xuefeng Qu
- Division of the Comprehensive Epilepsy Center and Neurofunctional Monitoring Laboratory, Department of Neurology, Peking University People's Hospital Beijing, China
| | - Jiaqing Yan
- School of Electrical and Control Engineering, North China University of Technology Beijing, China
| | - Xiaoli Li
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University Beijing, China
| | - Peixun Zhang
- Department of Trauma and Orthopaedics, Peking University People's Hospital Beijing, China
| | - Xianzeng Liu
- Division of the Comprehensive Epilepsy Center and Neurofunctional Monitoring Laboratory, Department of Neurology, Peking University People's Hospital Beijing, China
| |
Collapse
|
18
|
Vipin A, Kortelainen J, Al-Nashash H, Chua SM, Thow X, Manivannan J, Astrid, Thakor NV, Kerr CL, All AH. Prolonged Local Hypothermia Has No Long-Term Adverse Effect on the Spinal Cord. Ther Hypothermia Temp Manag 2015; 5:152-62. [PMID: 26057714 DOI: 10.1089/ther.2015.0005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hypothermia is known to be neuroprotective and is one of the most effective and promising first-line treatments for central nervous system (CNS) trauma. At present, induction of local hypothermia, as opposed to general hypothermia, is more desired because of its ease of application and safety; fewer side effects and an absence of severe complications have been noted. Local hypothermia involves temperature reduction of a small and specific segment of the spinal cord. Our group has previously shown the neuroprotective effect of short-term, acute moderate general hypothermia through improvements in electrophysiological and motor behavioral assessments, as well as histological examination following contusive spinal cord injury (SCI) in rats. We have also shown the benefit of using short-term local hypothermia versus short-term general hypothermia post-acute SCI. The overall neuroprotective benefit of hypothermia can be categorized into three main components: (1) induction modality, general versus local, (2) invasive, semi-invasive or noninvasive, and (3) duration of hypothermia induction. In this study, a series of experiments were designed to investigate the feasibility, long-term safety, as well as eventual complications and side effects of prolonged, semi-invasive, moderate local hypothermia (30°C±0.5°C for 5 and 8 hours) in rats with uninjured spinal cord while maintaining their core temperature at 37°C±0.5°C. The weekly somatosensory evoked potential and motor behavioral (Basso, Beattie and Bresnahan) assessments of rats that underwent 5 and 8 hours of semi-invasive local hypothermia, which revealed no statistically significant changes in electrical conductivity and behavioral outcomes. In addition, 4 weeks after local hypothermia induction, histological examination showed no anatomical damages or morphological changes in their spinal cord structure and parenchyma. We concluded that this method of prolonged local hypothermia is feasible, safe, and has the potential for clinical translation.
Collapse
Affiliation(s)
- Ashwati Vipin
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore, Singapore
| | - Jukka Kortelainen
- 2 Biomedical Engineering Research Group, Department of Computer Science and Engineering, University of Oulu , Oulu, Finland
| | - Hasan Al-Nashash
- 3 Department of Electrical Engineering, American University of Sharjah , Sharjah, United Arab Emirates
| | - Soo Min Chua
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore, Singapore
| | - Xinyuan Thow
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore, Singapore
| | - Janani Manivannan
- 4 Department of Orthopedic Surgery, National University of Singapore , Singapore, Singapore
| | - Astrid
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore, Singapore
| | - Nitish V Thakor
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore, Singapore .,5 Department of Biomedical Engineering, Johns Hopkins School of Medicine , Baltimore, Maryland
| | - Candace L Kerr
- 6 Department of Biochemistry and Molecular Biology, University of Maryland , Baltimore, Maryland
| | - Angelo H All
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore, Singapore .,4 Department of Orthopedic Surgery, National University of Singapore , Singapore, Singapore .,5 Department of Biomedical Engineering, Johns Hopkins School of Medicine , Baltimore, Maryland.,7 Department of Biomedical Engineering, National University of Singapore , Singapore, Singapore .,8 Division of Neurology, Department of Medicine, National University of Singapore , Singapore, Singapore .,9 Department of Neurology, Johns Hopkins School of Medicine , Baltimore, Maryland
| |
Collapse
|
19
|
Kortelainen J, Al-Nashash H, Vipin A, Thow XY, All A. The effect of anaesthesia on somatosensory evoked potential measurement in a rat model. Lab Anim 2015; 50:63-6. [DOI: 10.1177/0023677215589514] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Somatosensory evoked potentials (SEPs) are widely used to study the functional integrity of ascending sensory pathways. For animal studies, SEPs provide a convenient method to quantitatively assess the functionality of the nervous system with low invasiveness. Even though they are frequently used in animal models, little attention is paid to the fact that SEPs are vulnerable to contamination from experimental factors such as anaesthetic delivery. In this study, the effect of isoflurane on SEP measurement was investigated in a rat model. The aim was to find out the adjustments for anaesthetic delivery optimizing the quality of the recordings. Two aspects were studied: the effect of isoflurane dosage on the SEP parameters and on the repeatability of the measurements. The SEP quality was found to be best when 1.5% isoflurane concentration was used. This dosage resulted in the best signal-to-noise ratio and equal repeatability of the measurements compared with the others. Our findings can help in refining the anaesthetic protocols related to SEP recordings in a rat model and, by improving the quality of the measurements, potentially reducing the number of subjects needed to carry out studies.
Collapse
Affiliation(s)
- Jukka Kortelainen
- Biomedical Engineering Research Group, Department of Computer Science and Engineering, University of Oulu, Oulu, Finland
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, Singapore
| | - Hasan Al-Nashash
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, Singapore
- Department of Electrical Engineering, American University of Sharjah, Sharjah, United Arab Emirates
| | - Ashwati Vipin
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, Singapore
| | - Xin Yuan Thow
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, Singapore
| | - Angelo All
- Department of Orthopedic Surgery and Biomedical Engineering, National University of Singapore, Singapore
- Department of Neurology and Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
20
|
Wang D, Zhang J. Electrophysiological functional recovery in a rat model of spinal cord hemisection injury following bone marrow-derived mesenchymal stem cell transplantation under hypothermia. Neural Regen Res 2015; 7:749-55. [PMID: 25737697 PMCID: PMC4345656 DOI: 10.3969/j.issn.1673-5374.2012.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 02/24/2012] [Indexed: 12/12/2022] Open
Abstract
Following successful establishment of a rat model of spinal cord hemisection injury by resecting right spinal cord tissues, bone marrow stem cells were transplanted into the spinal cord lesions via the caudal vein while maintaining rectal temperature at 34 ± 0.5°C for 6 hours (mild hypothermia). Hematoxylin-eosin staining showed that astrocytes gathered around the injury site and formed scars at 4 weeks post-transplantation. Compared with rats transplanted with bone marrow stem cells under normal temperature, rats transplanted with bone marrow stem cells under hypothermia showed increased numbers of proliferating cells (bromodeoxyuridine-positive cells), better recovery of somatosensory-evoked and motor-evoked potentials, greater Basso, Beattie, and Bresnahan locomotor rating scores, and an increased degree of angle in the incline plate test. These findings suggested that hypothermia combined with bone marrow mesenchymal stem cells transplantation effectively promoted electrical conduction and nerve functional repair in a rat model of spinal cord hemisection injury.
Collapse
Affiliation(s)
- Dong Wang
- Department of Neurosurgery, Tianjin Fourth Central Hospital, Tianjin 300140, China
| | - Jianjun Zhang
- Department of Neurosurgery, Tianjin Fourth Central Hospital, Tianjin 300140, China
| |
Collapse
|
21
|
Bazley FA, Pashai N, Kerr CL, All AH. The effects of local and general hypothermia on temperature profiles of the central nervous system following spinal cord injury in rats. Ther Hypothermia Temp Manag 2014; 4:115-24. [PMID: 25019643 DOI: 10.1089/ther.2014.0002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Local and general hypothermia are used to treat spinal cord injury (SCI), as well as other neurological traumas. While hypothermia is known to provide significant therapeutic benefits due to its neuroprotective nature, it is unclear how the treatment may affect healthy tissues or whether it may cause undesired temperature changes in areas of the body that are not the targets of treatment. We performed 2-hour moderate general hypothermia (32°C core) or local hypothermia (30°C spinal cord) on rats that had received either a moderate contusive SCI or laminectomy (control) while monitoring temperatures at three sites: the core, spinal cord, and cortex. First, we identified that injured rats that received general hypothermia exhibited larger temperature drops at the spinal cord (-3.65°C, 95% confidence intervals [CIs] -3.72, -3.58) and cortex (-3.64°C, CIs -3.73, -3.55) than uninjured rats (spinal cord: -3.17°C, CIs -3.24, -3.10; cortex: -3.26°C, CIs -3.34, -3.17). This was found due to elevated baseline temperatures in the injured group, which could be due to inflammation. Second, both general hypothermia and local hypothermia caused a significant reduction in the cortical temperature (-3.64°C and -1.18°C, respectively), although local hypothermia caused a significantly lower drop in cortical temperature than general hypothermia (p<0.001). Lastly, the rates of rewarming of the cord were not significantly different among the methods or injury groups that were tested; the mean rate of rewarming was 0.13±0.1°C/min. In conclusion, local hypothermia may be more suitable for longer durations of hypothermia treatment for SCI to reduce temperature changes in healthy tissues, including the cortex.
Collapse
Affiliation(s)
- Faith A Bazley
- 1 Singapore Institute for Neurotechnology, National University of Singapore , Singapore
| | | | | | | |
Collapse
|
22
|
Bazley FA, Maybhate A, Tan CS, Thakor NV, Kerr C, All AH. Enhancement of bilateral cortical somatosensory evoked potentials to intact forelimb stimulation following thoracic contusion spinal cord injury in rats. IEEE Trans Neural Syst Rehabil Eng 2014; 22:953-64. [PMID: 24801738 DOI: 10.1109/tnsre.2014.2319313] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The adult central nervous system is capable of significant reorganization and adaptation following neurotrauma. After a thoracic contusive spinal cord injury (SCI) neuropathways that innervate the cord below the epicenter of injury are damaged, with minimal prospects for functional recovery. In contrast, pathways above the site of injury remain intact and may undergo adaptive changes in response to injury. We used cortical somatosensory evoked potentials (SSEPs) to evaluate changes in intact forelimb pathways. Rats received a midline contusion SCI, unilateral contusion SCI, or laminectomy with no contusion at the T8 level and were monitored for 28 days post-injury. In the midline injury group, SSEPs recorded from the contralateral forelimb region of the primary somatosensory cortex were 59.7% (CI 34.7%, 84.8%; c(2) = 21.9; dof = 1; p = 2.9 ×10(-6)) greater than the laminectomy group; SSEPs from the ipsilateral somatosensory cortex were 47.6% (CI 18.3%, 77%; c(2) = 10.1; dof = 1; p = 0.001) greater. Activation of the ipsilateral somatosensory cortex was further supported by BOLD-fMRI, which showed increased oxygenation at the ipsilateral hemisphere at day seven post-injury. In the unilateral injury group, ipsilesional side was compared to the contralesional side. SSEPs on day 14 (148%; CI 111%, 185%) and day 21 (137%; CI 110%, 163%) for ipsilesional forelimb stimulation were significantly increased over baseline (100%). SSEPs recorded from the hindlimb sensory cortex upon ipsilesional stimulation were 33.9% (CI 14.3%, 53.4%; c(2) = 11.6; dof = 1; p = 0.0007) greater than contralesional stimulation. Therefore, these results demonstrate the ability of SSEPs to detect significant enhancements in the activation of forelimb sensory pathways following both midline and unilateral contusive SCI at T8. Reorganization of forelimb pathways may occur after thoracic SCI, which SSEPs can monitor to aid the development of future therapies.
Collapse
|
23
|
Ng KA, Xu YP. A compact, low input capacitance neural recording amplifier. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2013; 7:610-620. [PMID: 24144666 DOI: 10.1109/tbcas.2013.2280066] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Conventional capacitively coupled neural recording amplifiers often present a large input load capacitance to the neural signal source and hence take up large circuit area. They suffer due to the unavoidable trade-off between the input capacitance and chip area versus the amplifier gain. In this work, this trade-off is relaxed by replacing the single feedback capacitor with a clamped T-capacitor network. With this simple modification, the proposed amplifier can achieve the same mid-band gain with less input capacitance, resulting in a higher input impedance and a smaller silicon area. Prototype neural recording amplifiers based on this proposal were fabricated in 0.35 μm CMOS, and their performance is reported. The amplifiers occupy smaller area and have lower input loading capacitance compared to conventional neural amplifiers. One of the proposed amplifiers occupies merely 0.056 mm(2). It achieves 38.1-dB mid-band gain with 1.6 pF input capacitance, and hence has an effective feedback capacitance of 20 fF. Consuming 6 μW, it has an input referred noise of 13.3 μVrms over 8.5 kHz bandwidth and NEF of 7.87. In-vivo recordings from animal experiments are also demonstrated.
Collapse
|
24
|
Bazley FA, Pourmorteza A, Gupta S, Pashai N, Kerr C, All AH. DTI for assessing axonal integrity after contusive spinal cord injury and transplantation of oligodendrocyte progenitor cells. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2012:82-5. [PMID: 23365837 DOI: 10.1109/embc.2012.6345876] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We describe the feasibility of using diffusion tensor magnetic resonance imaging (DT-MRI) to study a contusive model of rat spinal cord injury following human stem cell transplantation at and around the site of injury. Rats receiving either a laminectomy or contusion injury were transplanted with oligodendrocyte precursor cells (OPCs). During the course of the study, bioluminescence imaging (BLI; up to 100 days) and somatosensory evoked potentials (SSEPs; up to 42 days) were used to evaluate cell survival and functional outcomes. Spinal cords were then analyzed ex vivo upon termination using diffusion tensor imaging (DTI). Improvements in fractional anisotropy (FA) at day 100 post-transplantation corresponded with cell survival and functional SSEP improvements. Thus, we illustrate the feasibility of DTI for evaluating axonal integrity in SCI after cell replacement therapies, and we provide examples utilizing OPC transplantations in a contusion rat model.
Collapse
Affiliation(s)
- Faith A Bazley
- Dept. of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
| | | | | | | | | | | |
Collapse
|
25
|
All AH, Bazley FA, Gupta S, Pashai N, Hu C, Pourmorteza A, Kerr C. Human embryonic stem cell-derived oligodendrocyte progenitors aid in functional recovery of sensory pathways following contusive spinal cord injury. PLoS One 2012; 7:e47645. [PMID: 23091637 PMCID: PMC3473046 DOI: 10.1371/journal.pone.0047645] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 09/12/2012] [Indexed: 02/07/2023] Open
Abstract
Background Transplantations of human stem cell derivatives have been widely investigated in rodent models for the potential restoration of function of neural pathways after spinal cord injury (SCI). Studies have already demonstrated cells survival following transplantation in SCI. We sought to evaluate survival and potential therapeutic effects of transplanted human embryonic stem (hES) cell-derived oligodendrocyte progenitor cells (OPCs) in a contusive injury in rats. Bioluminescence imaging was utilized to verify survivability of cells up to 4 weeks, and somatosensory evoked potential (SSEPs) were recorded at the cortex to monitor function of sensory pathways throughout the 6-week recovery period. Principal Findings hES cells were transduced with the firefly luciferase gene and differentiated into OPCs. OPCs were transplanted into the lesion epicenter of rat spinal cords 2 hours after inducing a moderate contusive SCI. The hES-treatment group showed improved SSEPs, including increased amplitude and decreased latencies, compared to the control group. The bioluminescence of transplanted OPCs decreased by 97% in the injured spinal cord compared to only 80% when injected into an uninjured spinal cord. Bioluminescence increased in both experimental groups such that by week 3, no statistical difference was detected, signifying that the cells survived and proliferated independent of injury. Post-mortem histology of the spinal cords showed integration of human cells expressing mature oligodendrocyte markers and myelin basic protein without the expression of markers for astrocytes (GFAP) or pluripotent cells (OCT4). Conclusions hES-derived OPCs transplanted 2 hours after contusive SCI survive and differentiate into OLs that produce MBP. Treated rats demonstrated functional improvements in SSEP amplitudes and latencies compared to controls as early as 1 week post-injury. Finally, the hostile injury microenvironment at 2 hours post-injury initially caused increased cell death but did not affect the long-term cell proliferation or survival, indicating that cells can be transplanted sooner than conventionally accepted.
Collapse
Affiliation(s)
- Angelo H. All
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (AA); (CK)
| | - Faith A. Bazley
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Siddharth Gupta
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Nikta Pashai
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Charles Hu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Amir Pourmorteza
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Candace Kerr
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, United States of America
- * E-mail: (AA); (CK)
| |
Collapse
|
26
|
Bazley FA, All AH, Thakor NV, Maybhate A. Plasticity associated changes in cortical somatosensory evoked potentials following spinal cord injury in rats. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2011:2005-8. [PMID: 22254728 DOI: 10.1109/iembs.2011.6090564] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Spinal cord injury (SCI) causes a number of physiological and neurological changes resulting in loss of sensorimotor function. Recent work has shown that the central nervous system is capable of plastic behaviors post-injury, including axonal regrowth and cortical remapping. Functional integrity of afferent sensory pathways can be quantified using cortical somatosensory evoked potentials (SSEPs) recorded upon peripheral limb stimulation. We implanted 15 rats with transcranial screw electrodes and recorded SSEPs from cortical regions corresponding to each limb before and after a mild or moderate contusion injury. We report a post-injury increase in the mean amplitude of cortical SSEPs upon forelimb stimulation. SSEP amplitudes for mild and moderate SCI groups increased by 183% ± 95% and 107% ± 38% over baseline, respectively, while hindlimb SSEPs decreased by 58% ± 14% and 79% ± 4%. In addition, we report increased SSEP amplitude measured from the anatomically adjacent hindlimb region upon forelimb stimulation (increase of 90% ± 19%). Our results show that previously allocated hindlimb cortical regions are now activated by forelimb stimulation, suggesting an expansion in the area of cortical forelimb representation into hindlimb regions after an injury. This result is indicative of adaptive plasticity in undamaged areas of the CNS following SCI.
Collapse
Affiliation(s)
- Faith A Bazley
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | | | | |
Collapse
|
27
|
Bayrakli F, Balaban H, Ozum U, Duger C, Topaktas S, Kars HZ. Etanercept treatment enhances clinical and neuroelectrophysiological recovery in partial spinal cord injury. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2012; 21:2588-93. [PMID: 22526707 DOI: 10.1007/s00586-012-2319-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 01/23/2012] [Accepted: 04/12/2012] [Indexed: 12/31/2022]
Abstract
PURPOSE To investigate the effect of an anti-TNF-α agent (etanercept) on recovery processes in a partial spinal cord injury (SCI) model using clinical and electrophysiological tests. METHODS Twenty-four New Zealand rabbits were divided into three groups: group 1 [SCI + 2 ml saline intramuscular (i.m.), n = 8], group 2 (SCI + 2.5 mg/kg etanercept, i.m., 2-4 h after SCI, n = 8) and group 3 (SCI + 2.5 mg/kg etanercept, i.m., 12-24 h after SCI, n = 8). Rabbits were evaluated before SCI, immediately after SCI, 1 week after, and 2 weeks after SCI, clinically by Tarlov scale and electrophysiologically by SEP. RESULTS Tarlov scores of groups 2 and 3 were significantly better than group 1, 2 weeks after SCI. SEP recovery was significantly better in groups 2 and 3 than group 1, 2 weeks after SCI. CONCLUSIONS These results show that blocking TNF-α mediated inflammation pathway by an anti-TNF-α agent enhances clinical and electrophysiological recovery processes in partial SCI model.
Collapse
Affiliation(s)
- Fatih Bayrakli
- Department of Neurosurgery, Cumhuriyet University School of Medicine, Sivas 58140, Turkey.
| | | | | | | | | | | |
Collapse
|
28
|
Bazley FA, Hu C, Maybhate A, Pourmorteza A, Pashai N, Thakor NV, Kerr CL, All AH. Electrophysiological evaluation of sensory and motor pathways after incomplete unilateral spinal cord contusion. J Neurosurg Spine 2012; 16:414-23. [PMID: 22303873 DOI: 10.3171/2012.1.spine11684] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Unilateral contusions represent an increasingly popular model for studying the pathways and recovery mechanisms of spinal cord injury (SCI). Current studies rely heavily on motor behavior scoring and histological evidence to make assessments. Electrophysiology represents one way to reliably quantify the functionality of motor pathways. The authors sought to quantify the functional integrity of the bilateral motor and sensory pathways following unilateral SCI by using measurements of motor and somatosensory evoked potentials (MEPs and SSEPs, respectively). METHODS Eighteen rats were randomly divided into 3 groups receiving a mild unilateral contusion, a mild midline contusion, or a laminectomy only (control). Contusions were induced at T-8 using a MASCIS impactor. Electrophysiological analysis, motor behavior scoring, and histological quantifications were then performed to identify relationships among pathway conductivity, motor function, and tissue preservation. RESULTS Hindlimb MEPs ipsilateral to the injury showed recovery by Day 28 after injury and corresponded to approximately 61% of spared corticospinal tract (CST) tissue. In contrast, MEPs of the midline-injured group did not recover, and correspondingly > 90% of the CST tissue was damaged. Somatosensory evoked potentials showed only a moderate reduction in amplitude, with no difference in latency for the pathways ipsilateral to injury. Furthermore, these SSEPs were significantly better than those of the midline-injured rats for the same amount of white matter damage. CONCLUSIONS Motor evoked potential recovery corresponded to the amount of spared CST in unilateral and midline injuries, but motor behavior consistently recovered independent of MEPs. These data support the idea that spared contralateral pathways aid in reducing the functional deficits of injured ipsilateral pathways and further support the idea of CNS plasticity.
Collapse
Affiliation(s)
- Faith A Bazley
- Departments of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Iyer S, Maybhate A, Presacco A, All AH. Multi-limb acquisition of motor evoked potentials and its application in spinal cord injury. J Neurosci Methods 2010; 193:210-6. [PMID: 20832429 DOI: 10.1016/j.jneumeth.2010.08.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 08/18/2010] [Accepted: 08/18/2010] [Indexed: 12/21/2022]
Abstract
The motor evoked potential (MEP) is an electrical response of peripheral neuro-muscular pathways to stimulation of the motor cortex. MEPs provide objective assessment of electrical conduction through the associated neural pathways, and therefore detect disruption due to a nervous system injury such as spinal cord injury (SCI). In our studies of SCI, we developed a novel, multi-channel set-up for MEP acquisition in rat models. Unlike existing electrophysiological systems for SCI assessment, the set-up allows for multi-channel MEP acquisition from all limbs of rats and enables longitudinal monitoring of injury and treatment for in vivo models of experimental SCI. The article describes the development of the set-up and discusses its capabilities to acquire MEPs in rat models of SCI. We demonstrate its use for MEP acquisition under two types of anesthesia as well as a range of cortical stimulation parameters, identifying parameters yielding consistent and reliable MEPs. To validate our set-up, MEPs were recorded from a group of 10 rats before and after contusive SCI. Upon contusion with moderate severity (12.5mm impact height), MEP amplitude decreased by 91.36±6.03%. A corresponding decline of 93.8±11.4% was seen in the motor behavioral score (BBB), a gold standard in rodent models of SCI.
Collapse
Affiliation(s)
- Shrivats Iyer
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | | | | |
Collapse
|